The present invention relates generally to sealing gaskets, and more particularly to a bulb-type sealing strip which is formed of a generally planar strip and snapped together for sealing an opening in a wall structure with a member adapted to close the opening and to carry the gasket.
While the gasket of this invention is suitable for many sealing applications, it is particularly useful for sealing large openings, such as are encountered in refrigerated railroad cars which are normally subjected to a rather hostile environment and abusive treatment, and which therefore may require replacement several times during the life of the structure which forms the compartment being sealed. And since the closure opening may be as large as 10 to 15 feet wide, the length of the sealing member components are long enough to make ordinary installation quite laborious. For example, it is not unusual for the lengths of gasket required for a single door to exceed 40 feet or more.
Up to the present time, two kinds of bulb-type gaskets have been known. One type is the ordinary gasket in which the center is hollow but the walls are continuously bonded. This type of a gasket must normally be a ready-made gasket which is ordered to size. Another form of gasket is extruded basically flat in the form of a ribbon and is rolled about its longitudinal axis and has edges that are inserted into brackets which are affixed to the door. This type of sealing system is disclosed in U.S. Pat. No. 3,562,957 which issued on Feb. 16, 1971.
Both of these prior art bulb-type gaskets have certain limitations, the continuously bonded type is very heavy and can usually not be provided in linear sections that are rolled up for assembly at the site and therefore is extremely heavy and has to be stored in all necessary sizes. The second type overcomes some of these disadvantages but still requires a metal retainer affixed to the door with facing channels which receive the flanges of the gasket in order maintain the gasket in the rolled up position, with special corners being provided.